Currently, a mobile communication apparatus such as a mobile telephone mainly includes a function of informing call incoming without using a ringing tone by the occurrence of somesthetic vibration as well as a function of informing call incoming using a ringing tone, and multi-function vibration actuators for applying these functions by a single device are used in a part of the models.
Among the above-described multi-function vibration actuators, as one of general structures, Japanese Patent No. 2929579 (hereinafter, referred to as Patent Document 1) is filed and registered, in which the shape of a suspension for supporting a magnetic circuit section having a magnet is partially changed so as to increase the linearity of the suspension, thereby obtaining good vibration characteristics.
In the multi-function vibration actuator described in Patent Document 1, since a planar shape is a rectangular shape, it is advantageous that a useless space on a mounting substrate upon mounting on a mobile telephone or the like is reduced.
In addition, in Japanese Unexamined Patent Application No. 2000-201396 (hereinafter, referred to as Patent Document 2), a planar shape is a track type such that it is possible to suppress a useless space on a mounting substrate while the area of a diaphragm is increased.
However, in the multi-function vibration actuators described in Patent Documents 1 and 2, each arm needs to be arranged along the outer circumference of a magnetic circuit supporting section due to the shape of the suspension, and a space in which the arm is arranged needs to be secured. Accordingly, it is difficult to reduce the arrangement space of the suspension.
In addition, by arranging the arm along the outer circumference of the magnetic circuit supporting section, since the vibration force works to a magnetic circuit section in a rotation direction when the magnetic circuit is driven, the amplitude of the magnetic circuit section may not be set large. Therefore, the vibration force which works to the inside of the suspension in a torsion direction may not be sufficiently used.
In addition, if the mounting space on the substrate is small, in the multi-function vibration actuator described in Patent Document 1, since the magnetic circuit is small, sufficient somesthetic vibration may not be obtained. In the multi-function vibration actuator described in Patent Document 2, the shape or the like of the suspension becomes complicated in order to suppress fluctuation of the magnetic circuit upon vibration.